An operation machine has been adapted such that, in the case where abnormality occurs in the operation machine, the abnormality is stored in a control device provided in the operation machine (e.g., Patent Literature 1).
A display device of an operation machine in Patent Literature 1 is adapted such that in the case where abnormality occurs in the operation machine during operation of the operation machine, abnormality information on the abnormality can be stored in a controller, and seen through the display device. As described, in the display device of the operation machine, abnormality information can be stored, whereas abnormality information stored in the display device can also be erased.